Method and apparatus for transmitting PPDU on basis of S-TDMA in wireless LAN system

1. A method for transmitting a Physical layer Protocol Data Unit (PPDU) based on Scheduled-Time Division Multiple Access (S-TDMA) in a wireless LAN system, the method comprising: transmitting, by an access point (AP), a trigger frame to a first station (STA) and a second STA; and receiving, by the AP, based on the trigger frame, a first trigger-based frame from the first STA and receiving a second trigger-based frame from the second STA, wherein the trigger frame includes a common information field and a user information field, wherein the common information field includes S-TDMA indication information on that the S-TDMA can be performed, wherein the user information field includes allocation information for a first resource unit (RU) to which the first trigger-based frame and the second trigger-based frame are to be transmitted, a first symbol offset information for the first trigger-based frame, and a second symbol offset information for the second trigger-based frame, wherein the first trigger-based frame is transmitted in the first RU based on the first symbol offset information, wherein the second trigger-based frame is transmitted in the first RU based on the second symbol offset information, wherein a guard time exists between the first trigger-based frame and the second trigger-based frame, wherein the guard time is configured as an SIFS, wherein, in case the guard time is shorter than a CS duration performing channel sensing (CS), if a channel is Busy during the CS duration, the second trigger-based frame is transmitted, and if the channel is Idle during the CS duration, the second trigger-based frame is not transmitted.

2. The method of claim 1, wherein the S-TDMA indication information includes a reserved bit within the trigger frame or includes a reserved bit within a trigger type subfield being included in the trigger frame.

3. The method of claim 1, wherein the first symbol offset information and the second symbol offset information are included in a Trigger Dependent User Info field being included in the user field.

10. A wireless device being an access point (AP) for transmitting/receiving a Physical layer Protocol Data Unit (PPDU) based on Scheduled-Time Division Multiple Access (S-TDMA) in a wireless LAN system, the wireless device comprising: a memory; a transceiver; and a processor being operatively coupled with the memory and the transceiver, wherein the processor: transmits a trigger frame to a first station (STA) and a second STA, and receives a first trigger-based frame from the first STA and receives a second trigger-based frame from the second STA, wherein the trigger frame includes a common information field and a user information field, wherein the common information field includes S-TDMA indication information on that the S-TDMA can be performed, wherein the user information field includes allocation information for a first resource unit (RU) to which the first trigger-based frame and the second trigger-based frame are to be transmitted, a first symbol offset information for the first trigger-based frame, and a second symbol offset information for the second trigger-based frame, wherein the first trigger-based frame is transmitted in the first RU based on the first symbol offset information, wherein the second trigger-based frame is transmitted in the first RU based on the second symbol offset information, wherein a guard time exists between the first trigger-based frame and the second trigger-based frame, wherein the guard time is configured as an SIFS, wherein, in case the guard time is shorter than a CS duration performing channel sensing (CS), if a channel is Busy during the CS duration, the second trigger-based frame is transmitted, and if the channel is Idle during the CS duration, the second trigger-based frame is not transmitted.

11. The wireless device of claim 10, wherein the S-TDMA indication information includes a reserved bit within the trigger frame or includes a reserved bit within a trigger type subfield being included in the trigger frame.

12. The wireless device of claim 10, wherein the first symbol offset information and the second symbol offset information are included in a Trigger Dependent User Info field being included in the user field.

13. A method for receiving a Physical layer Protocol Data Unit (PPDU) based on Scheduled-Time Division Multiple Access (S-TDMA) in a wireless LAN system, the method comprising: receiving, by a first station (STA), a trigger frame to an access point (AP); and transmitting, by the first STA, a first trigger-based frame based on the trigger frame, wherein the trigger frame includes a common information field and a user information field, wherein the common information field includes S-TDMA indication information on that the S-TDMA can be performed, wherein the user information field includes allocation information for a first resource unit (RU) to which the first trigger-based frame and the second trigger-based frame are to be transmitted, a first symbol offset information for the first trigger-based frame, and a second symbol offset information for the second trigger-based frame, wherein the first trigger-based frame is transmitted in the first RU based on the first symbol offset information, wherein the second trigger-based frame is transmitted in the first RU based on the second symbol offset information, wherein a guard time exists between the first trigger-based frame and the second trigger-based frame, wherein the guard time is configured as an SIFS, wherein, in case the guard time is shorter than a CS duration performing channel sensing (CS), if a channel is Busy during the CS duration, the second trigger-based frame is transmitted, and if the channel is Idle during the CS duration, the second trigger-based frame is not transmitted.